Nanomedicine and Nanotoxicology Group, Physics Institute of São Carlos (IFSC), University of São Paulo (USP), Brazil.
Nanomedicine and Nanotoxicology Group, Physics Institute of São Carlos (IFSC), University of São Paulo (USP), Brazil.
Environ Pollut. 2018 Dec;243(Pt A):723-733. doi: 10.1016/j.envpol.2018.09.020. Epub 2018 Sep 8.
The increase of production and consumption of copper oxide nanostructures in several areas contributes to their release into aquatic ecosystems. Toxic effects of copper oxide nanoparticles (CuO NPs), in particular, on tropical aquatic organisms are still unknown, representing a risk for biota. In this study, the effects of rod-shaped CuO NPs on the Neotropical species Ceriodaphnia silvestrii and Hyphessobrycon eques were investigated. We also compared the toxicity of CuO NPs and CuCl on these species to investigate the contribution of particles and cupper ions to the CuO NPs toxicity. Considering the low copper ions release from CuO NPs (<1%), our results revealed that the toxicity of CuO NPs to C. silvestrii and H. eques was mainly induced by the NPs. The 48 h EC for C. silvestrii was 12.6 ± 0.7 μg Cu L and for H. eques the 96 h LC was 211.4 ± 57.5 μg Cu L of CuO NPs. There was significant decrease in reproduction, feeding inhibition and increase in reactive oxidative species (ROS) generation in C. silvestrii exposed to CuO NPs. In fish H. eques, sublethal exposure to CuO NPs caused an increase in ROS generation in gill cells and an increase in cells number that were in early apoptotic and necrotic stages. Our results showed that CuO NPs caused toxic effects to C. silvestrii and H. eques and ROS play an important role in the toxicity pathway observed. Data also indicated that C. silvestrii was among the most sensitive species for CuO NPs. Based on predicted environmental concentration in water bodies, CuO NPs pose potential ecological risks for C. silvestrii and H. eques and other tropical freshwater organisms.
氧化铜纳米结构在多个领域的产量和消耗量的增加导致其释放到水生生态系统中。氧化铜纳米颗粒（CuO NPs）的毒性效应，特别是对热带水生生物的毒性效应仍不清楚，这对生物群构成了风险。在这项研究中，研究了棒状 CuO NPs 对新热带物种 Ceriodaphnia silvestrii 和 Hyphessobrycon eques 的影响。我们还比较了 CuO NPs 和 CuCl 对这些物种的毒性，以研究颗粒和铜离子对 CuO NPs 毒性的贡献。考虑到从 CuO NPs 释放的铜离子较少（<1%），我们的结果表明，CuO NPs 对 C. silvestrii 和 H. eques 的毒性主要是由 NPs 引起的。C. silvestrii 的 48 h EC 为 12.6 ± 0.7 μg Cu L，H. eques 的 96 h LC 为 211.4 ± 57.5 μg Cu L 的 CuO NPs。暴露于 CuO NPs 的 C. silvestrii 的繁殖减少，摄食受到抑制，活性氧（ROS）生成增加。在鱼类 H. eques 中，亚致死暴露于 CuO NPs 导致鳃细胞中 ROS 生成增加，处于早期凋亡和坏死阶段的细胞数量增加。我们的研究结果表明，CuO NPs 对 C. silvestrii 和 H. eques 产生了毒性作用，ROS 在观察到的毒性途径中发挥了重要作用。数据还表明，C. silvestrii 是对 CuO NPs 最敏感的物种之一。根据水体中的预测环境浓度，CuO NPs 对 C. silvestrii 和 H. eques 以及其他热带淡水生物构成潜在的生态风险。
